Product for surfacing roads



8 3 Patented Mar. 22, 1938 UNITED STATES tross Reference PATENT OFFICE PRODUCT FOR SURFACING ROADS Pierre Marcel Andr Laut, Puteaux, France,

assignor to Societe De Recherches & De Perfectionnements Industriels, Puteaux, France, a corporation of France No Drawing. Application June 6, 1934, Serial No. 729,339. In Switzerland June 12, 1933 5 Claims.

The present invention concerns a compound for the covering of roads, characterized by the fact that it is formed by an intimate mixture of constituents, the principal of which are a 455 or a product similar to tar, with water and a combustible filler, that means a filling substance in e state of afine powder, constituted particularly by coal.

The terms tar or a product similar to tea? is meant to include all matters which are common- 1y called tar, this term being understood in its widest sense, i. e., in that of the non-gaseous total or partial distillate 0; coal, v v gp d oil, schists or simi ar materials, for instance bitu'Ti'iens or asphaltum. On the other hand, the combustible filler may be added with non-combustible mineral matters, and the water may be added with various substances, particularly with emulsive and stabilizing substances. Furthermore, to the abovemm may be added, without departing from the invention, other substances, provided that their presence does not disturb the phenomenon of emulsion as described below.

According to the invention, the proportion of each of the principal constituents of the ternary mixture: water, tag; and filler, and more particularly the proportion of water, is variable according to the destination of the compound and according to the quality desired of each particular application. In the majority of cases, financial considerations and convenience of use lead to the choice of a proportion of water sufficiently great for giving the greatest possible fluidity to the mixture. The inventor has realized mixtures of water, tar and filler in which the quantity of water is approximately equal to the quantity of tar, but, for obtaining this result, it is necessary to add to the mixture an emulsive agent such as soap, alkaline resinate or oleate, sodium silicate, employed eitl ier alone or with a smal quanti y of matter such as carrageen, carobbean etc. endowed with stabilizing properties and added, eventually, with :tluxing oil.

At the same time it is advantageous, conceml ing the proportion of combustible filler in the mixture, not to depart from the proportion corresponding to 37 to 38 volumes of filler for 62 to 63 volumes of tar, in order to realize the most suitable viscosifir? Without departing from the invention, other proportion of water and filler, ranging from zero to the two approximate limits indicated above may also be used; reasons of economy and of a better conservation of the road covering are however important considerations.

The mixture may be obtained by first heating the water and the tar and by mixing them before incorporating the YE}. The inventor has found that a particularly advantageous process of operation consists in heating first the tar together with an alkali, for instance caustic soda. if the nature of the tar should demand is facilitates the starting of the emulsion, and then adding the water which contains an gn ilgve agent and, eventually, also a stabilizing agent as iiTdic'a'ted above. T

Example In a mixer 570 kgs. anhydrous tar, such as road tar corresponding to the specifications of the *Tdministration irancaise des Ponts et Chausses", are heated to about 90 C., and in another vessel, 550 to 600 kgs. of water are brought very near to boiling. In this nearly boiling water is poured a small quantity of a mixture of commercial black soap added with a small proportion of carrageen ell obtained by sifting and cooling a Boiling solution saturated with carrageen. The mixture: black soap and carrageen acting as an emulsive and stabilizin a ent, is added in the mm of aB'o uFsix one-thousandths of the total weight of the mixture. Then about 5 to 10 kgs. of ordinary commercial c a us t ic s2da are poured into the mixer containing thetar and the mixture is stirred. The soapy solution is then poured into the warm tar while stirring by means of the stirrer. The emulsion of tar in water being formed, and the temperature being maintained at about 85 to 90 C., one now pours progressively 300 kgs. of carbon filler having the following characteristics:

Percent Content in ashes 14 Content in volatile matters 25 Granulometric analysis Per cent Residue on the IOU-mesh sieve 0,5 Residue on the 200-mesh sieve 21,3 Residue on the 300-mesh sieve 25,6 Accepted on the 300-mesh sieve 52,6

After the mixture has been stirred for another quarter of an hour, the spreading of this mixture is effected at a temperature near to 85 C. in a spreader of the type usually employed for spreading of ordinary tar, at the rate of about 1 kg. per square meter of road surface. Gravel is spread immediately after the spreading of the mixture and the gravel thereby adheres to the emulsion immediately, with sufficient force for enabling a motor lorry to pass over the still fresh covering txaminer 106. cowosmons, Ems-. Ref ree "or manipulation.

COATING OR PLASTIC 2 without detaching any gravel or causing any spraying of the emulsion.

The proportion of the emulsive and stabilizing agents indicated in the above case is only cited by way of example. It may be higher or lower according to the nature of the constituents: tar, water, filler to be used. It is, however, advisable to keep to the minimum quantity of emulsive and stabilizing agents, not only for reasons of economy, but also in order to avoid a washing out of these products and their sweeping away by the rain water.

In the above example, the alkali has been separately added to the tar, and the emulsive and stabilizing agent to the water. Without departing from the invention, however, a mixture may be prepared in advance of the three above additional substances: alkali, emulsive and stabilizing agents for reas'ohsofYonvenience andzifs'e'- One may, for instance, melt first caustic soda and then add in small quantities to the latter first black soap by stirring, then carrageei j elly. Alter mTxTrYg for some minutes, a complex solid body is obtained in the form of grains which may be easily manipulated with a spade and transported in barrels. At the place where the product is to be used, the desired proportion of this compound may be dissolved in the amount of water required for forming the final mixture. The compound body may, however, also be dissolved in a small quantity of warm water, this saturated solution being thereupon added to the tar and the preparation of the mixture being afterwards ended by adding the complementary amount of water and the filler under continued stirring.

Without departing from the invention, the order of the operations may be varied, for instance by introducing the compound into warm water, pouring the tar into the water and ending with the filler, or alternatively incorporating the filler before pouring the tar.

The emulsion cited as an example in the above is stable under heat conditions, but there is a temperature below which it breaks up; this temperature, in almost all cases, is between 25 and 75 C., it varies according to the nature and more particularly according to the viscosity of the utilized tar and also according to the geological nature of the filler. The emulsion is therefore suited for the cases, which are most frequent where it may be made near enough to the place of utilization so as to be kept warm after it has been made and that it may be transported to the place of utilization without permitting its temperature to drop below the limit of breaking up. But there are cases where it is necessary to lower further the temperature-limit to where the breaking up takes place, and more particularly to lower this limit down to the neighbourhood of or below the surrounding temperature. In certain cases the inventor has found that it is possible to obtain such a result provided a certain quantity of resin is used with fiuxing oil, with or without addition of carrageen as emulsive or stabilizing agent. One may utilize as fiuxing oil a petroleum oil, such as gas-oil, or a li ht or medfum coTl 011, or also a solvent sucfi as carbon sEl HiHe, carbon tetrachloride and benzol, by observing, however, the law consisting to introduce the fluxing body only when the liquid mixture will no longer have a tendency to pass beyond the boiling temperature of the employed fluxing or solving agent. In a general manner, the use of a fluxing agent is necessary -market such as s1imes.

if a bitumen is used as principal hydrocarbon constituent of the final mixture.

One of the efiects of the use of such a fluxing or solving agent is the lowering of the viscosity of the mixture: water, tar and filler, for allowing it to be spread without warming it up, or with warming it up slightly to a low temperature, and more particularly to the surrounding temperature. It is to be noted that such an emulsion which is thus rendered stable and usable when cold may become unstable when warm, contrarily to the emulsions usually used for the covering of roads, among which the emulsions of bitumen may be cited.

The preparation of the composition may, in most of the cases, be realized entirely at cold temperature if a fluxing oil containing resin in solution is employed.

A particular case for the use of the invention consists in utilizing such tarslzhat contain naturally an important percentage of water; this is the case of the crude tars which generally contain more than 0 0 water, and of the tars obtained from the distillation of coal in the eiov vy g retorts'br those of the ji gin- Duckham type, with or without addition of water, and whose water-content may attain 40% in certain cases. The use of such hydrated tars utilized alone does not give any good results. Not

only do they dry quickly, but the evaporation of filler mixed with a hydrated tar of this Elnd'ahd the proportion of which may attain a volume up to 40% carbon against 60% of anh drous tar. The drying takes place rapidly and the cov' ering maintains its plasticity and its other desirable qualities for a longer time.

Another particular case for the application of the invention consists in the utilization of products obtained in the washing plants for coal, and for which it is generally diflicult to find a These slimes are, if necessary, brought to the desired degree of fineness by a grinding up, preferably under wet conditions, and then worked up in water at a temperature which may attain C., warm tar being incorporated during the working up. If the slimes are too rich in ashes, it may be advantageous to eliminate a certain amount of the churning provides a convenient means for such an elimination; at the same time it is possible to extract the major part of the water which contains the majorpart of the ashes in suspension. Tar is again added in order to obtain a, mixture containing for instance about 40 volumes of carbon against 60 volumes of tar and a water-content of 10% for instance of the mixture tarcarbon and water.

One will, of course, eventually add to the mixture either an emulsive or a stabilizing agent, or both together.

The products described above may be spread with the same apparatus and in the same proportions per square meter as the tar utilized alone. They present a great superiority with respect to the tar alone, from the point of view of the rapidity of drying, as well as of the absence of sweating, of the non-skidding qualities Examiner and of the useful life of the covering, or in other words rapid aging as compared to the tar alone. Lastly, due to the utilization of an important percentage of carbon filler price of which is lower than that of tar, and also due to the possibility of spreading the mixture at low temperature and in low proportions, the invention provides a binder which is particularly economical for the covering of roads.

The products of the present invention may be utilized by superficial spreading by means of the usual spreading gear followed by spreading of sand or gravel, or in connection with tar macadams or bituminous concretes or in any other suitable manner.

What I claim is:

1. A product for the surfacing of roads constituted by a stable emulsion in water of a bituminous material selected from the group consisting of tar, bitumen and asphaltum, said emulsion containing, in a stable suspension and in a proportion comprising 10% to 40% of the total volume of the product, a finely pulverized coal filler present in the product in the non-dissolved state, its presence not disturbing the stability of the emulsion before the using of the product on the road.

2. A product for the surfacing of roads constituted by a stable emulsion in water of a bituminous material selected from the group conabout 1 to 2 volumes of coal filler for l to 3 volumes of the bituminous material, the quantity of the bituminous material being at least equal to that of the coal filler.

3. A product for the surfacing of roads constituted by a stable emulsion in water of a bituminous material selected from the group consisting of tar, bitumen and asphaltum, said emulsion containing in a stable suspension a finely pulverized coal filler present in the product in the non-dissolved state and in a proportion comprising 10% to of the total volume of the product, an emulsive agent selected from the group consisting of soap, caustic soda, alkaline resinate, alkaline oleate and sodium silicate, and a stabilizing agent selected from the group consisting of carrageen, carobbean and. resin.

4. A product for the surfacing of roads constituted by a stable emulsion in water of a bituminous material selected from the group consisting of tar, bitumen and asphaltum, said emulsion containing in a stable suspension a finely pulverized coal filler present in the product in the non-dissolved state and in a proportion comprising 10% to 40% of the total volume of the product, an emulsive agent selected from the group consisting of soap, caustic soda, alkaline resinate, alkaline oleate and sodium silicate, a stabilizing agent selected from the group consisting of carrageen, carobbean and resin, and a fiuxing agent.

5. A product for the surfacing of roads constituted by a stable emulsion of about 570 parts by weight of anhydrous tar in about 550 to 600 parts by weight of water, said emulsion containing also about 300 parts by weight of a finely pulverized coal filler, about 5 to 10 parts by weight of caustic soda and 6/1000 of the total weight of the product of carrageen jelly.

PIERRE MARCEL ANDRE LE AUTE L 

